Re: [PATCH 4/5] ext4: fallocate support in ext4

[Jeff Garzik <jeff@xxxxxxxxxx>]

Andreas Dilger wrote:
> On May 07, 2007  13:58 -0700, Andrew Morton wrote:
> > Final point: it's fairly disappointing that the present implementation is
> > ext4-only, and extent-only.  I do think we should be aiming at an ext4
> > bitmap-based implementation and an ext3 implementation.
>
> Actually, this is a non-issue.  The reason that it is handled for 
> extent-only
> is that this is the only way to allocate space in the filesystem without
> doing the explicit zeroing.  For other filesystems (including ext3 and

Precisely /how/ do you avoid the zeroing issue, for extents?

If I posix_fallocate() 20GB on ext4, it damn well better be zeroed, 
otherwise the implementation is broken.

        Jeff